Øystein Grøvlen is a Senior Principal Software Engineer in the MySQL group at Oracle, where he works on the MySQL Query Optimizer. Dr. Grøvlen has a PhD in Computer Science from the Norwegian University of Science and Technology. Before joining the MySQL team 9 years ago, he was a contributor on the Apache Derby project and Sun's Architectural Lead on Java DB. Prior to that, he worked for 10 years on the development of Clustra, a highly available DBMS. Øystein lives in Trondheim, Norway.